1. Technical Field
The present invention relates to an ink-circulation type inkjet printing apparatus.
2. Related Art
An ink-circulation type inkjet printing apparatus is known which performs printing by discharging ink from an inkjet head while circulating ink.
As the ink-circulation type inkjet printing apparatus, there is one that includes a pressurizing tank and a negative-pressure tank arranged below the inkjet head, and an air pump for feeding air from the negative-pressure tank to the pressurizing tank (see Patent Literature 1, for example).
In this type of inkjet printing apparatus, a negative pressure and a positive pressure are applied to the negative-pressure tank and the pressurizing tank, respectively, by feeding air from the negative-pressure tank to the pressurizing tank by the air pump when printing is performed. As a result, ink flows from the pressurizing tank toward the inkjet head. The ink not consumed in the inkjet head is recovered into the negative-pressure tank. The ink is fed from the negative-pressure tank to the pressurizing tank by the ink pump. Ink is thus circulated.
In this type of inkjet printing apparatus, since the pressurizing tank and the negative-pressure tank are arranged below the inkjet head, overflow of the ink from a nozzle of the inkjet head during standby can be avoided.